English
For NormOneClass 𝕜, balancedHull 𝕜 (s + t) ⊆ balancedHull 𝕜 s + balancedHull 𝕜 t.
Русский
Для нормальной единичной нормы 𝕜: balancedHull 𝕜 (s + t) ⊆ balancedHull 𝕜 s + balancedHull 𝕜 t.
LaTeX
$$$[NormOneClass 𝕜]\\ balancedHull\\ 𝕜 (s + t) \\subseteq balancedHull\\ 𝕜\\ s + balancedHull\\ 𝕜\\ t$$$
Lean4
theorem balancedHull_add_subset [NormOneClass 𝕜] {t : Set E} :
balancedHull 𝕜 (s + t) ⊆ balancedHull 𝕜 s + balancedHull 𝕜 t :=
balancedHull_subset_of_subset (add (balancedHull.balanced _) (balancedHull.balanced _))
(add_subset_add (subset_balancedHull _) (subset_balancedHull _))